dorey



G. B. DOREY.

FRICTION DRAFT RIGGING.

APPLICATION man MAH, |921.

Patented Apr. 18, 1922.

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Patented Apr. 18, 1922.

2 SHEETS-SHEET 2.

I.. 2 G9 N1. M7. -GY ViII^ man Tl 0F@ DML DF BNN 000, Gl Tl A ww Rm.. FP A WIT/V 555 UNITED STATES PATENT OFFICE.

rmo'rroiv DRAFT RIGGING.

.Application filed May 7, 1921.

To all 'whom t may concern.' i

Be it known that I, Geenen BINET Dormir, a subject of the King of Great Britain, and residing in the city of Montreal, Province of Quebec7 Dominion of Canada, have invented certain new and useful Improve ments in Friction Draft Riggings, and Ado hereby declare the following to be a full, clear, and exact description of the same.

My invention relates to improvements in friction draft riggings for railway cars and is especially related to that class wherein wedging elements are used in connection with casings or central columns to createv frictional resistance. In gears of the identified type it is common practice to incline the walls of the casing and have the wedges re-act with great force transverselyof the casing tending to split 'the same. With the increasing capacity of the draft gear it is now found that the casings cannot be made sufiiciently'strong to withstand this excessive strain and still ybe contained within the limited space provided in the modern car.

It is an object of this invention to partially relieve the casing of this excessive strain by mounting a movable wedge retaining member adapted to take the major portion of the transverse strain.A

Another object of this invention is to provide a column within the casing to receive a portion of the load during the compression of the gear and to provide suitable means whereby the casing and this column will work together and each take. a proportion of the load.

A further object of the invention is to provide friction elements having a short travel and adapt the same to displace other friction elements a correspondingly greater distance and at a relatively greater speed.

A further object of the invention is to provide a friction draft rigging which will vbe certain to release after compression. A difficulty hitherto experienced in friction draft gears of high capacity has been the liability of the wedges binding and preventing the gear from returning to normal position. In this invention full provision has been made to guard against this weakness by having the friction elements in two series, one of low speed and low frictional capacity and the other of high speed and high frictional capacity and Specification of Letters Patent.

Patented Apr. 18, 1922.

serial No. 467,620.

adapting the same to work in unison under compression but permitting the low velocity member' to release independently of the other.v

Further my invention consists in certain novelties of rdesign and construction and combinations of parts as will be more particularly set forth hereinafter and claimed.

The accompanying drawings illustrate an example of the physical embodiment of the invention constructed and arranged to the best mode of procedure l have so far devised for the purpose.

Figure l. is a longitudinal sectional view through the complete gear as assembled, the parts being in the normal extended or release position.

Figure 2. is a'sectional view taken on line 22 of Figure 3.

Figure 3. is a view similar to Figure l. showing the gear under full compression.

Figure 4. is a longitudinal view showing the gear in the early stage of the release operation with the coupler returned to the normal position by the outer spring and the inner frictional members in the closed position.

Figure 5. is a perspective vie-w of the casing.

Figure 6. is a perspective view of the wedge block pressure transmitting member.

Figure 7. is a perspective view of the wedge retaining member.

Figure 8. is a perspective view showing in assembly relation the friction shoes.

In the drawings 2 represents the drawbar of the coupler connected by means of key 3 to the yoke L in the accepted manner, the yoke embracing casing 5 and the whole being located between center sills 6 and 7. The rear of the casing is formed to abut against rear stops 8 an d 9 which are secured to the center sills, front stops l0 and ll also secured to the center sills constitute draft gear abutments under pulling strains.

The casing or housing 5 is preferably formed of rectangular shape with one end closed and the other end open and formed with two oppositely beveled pieces 12 which extend for a considerable distance within the housing. These beveled portions have angular shaped recesses 13 formed therein thereby permitting the insertion of springs and other parts within the housing. The bottom .of the casing isV formed with a con,

cave recess 111 which forms a seating for central post or column member 15 which eX tends longitudinally within thecasing. rlhis column is formed with a head having theV outside convex as at 16 and bearing ,within concave recess 141;7 4a limited amount of inon tion in all directions being thereby rendered pos-sible. Encircling this column inner springs 27 bear on the reverse side of the column bearing which is formed with a flat portion 17 for this purpose. The otherI end of this spring bears on the end of a plurality of friction shoes 18 directly resisting inward movement of these members.l The friction shoes 18 are preferably formed in four parts as shown in Figure 8 and surround column 15 frictionally engaging the same at suru face 19 and being held in close frictional engagement therewith by means of wedge retaining member 2O and spring 21 co operating with wedge block pressure transmitting members 22. The friction shoes 18 are formed at their inner end with exterior wedge surfaces 23 preferably in the form of a frustum of a cone and these register with similarly tapered interior surfaces 24 vof wedge retaining member 2O by means of which pressure applied in a longitudinal direction is resolved into a transverse force causing the shoes to bear againstthe column member. At their outer ends the friction shoes are also formed wedge shaped and in this instance the surface of the wedge portion 25 is preferably made flat to make lcontact with the wedge surface 26 of wedge block pressure transmitting members 22.

`Wedge block pressure transmitting menibers 22 are ldisposed on each side of the longitudinal center of the gear and are each formed with a bearing surface 28 constituting one face of a wedge. These bearing surfaces bear on the beveled surfaces 12 of the casing and the wedge bloclrs are thereby y.caused to move inwardly and transversely towards each other when the gear `is being compressed. Flanges 29 are formed at the top and bottom of the wedge blocks forming a channel shape between which friction shoes 18 are disposed Vand thereby guided and further this lip or flange forms a covering sealing the aperture between the 'friction faces 25 and 26 and serves to exclude particles of dust and coal from enteringthere between. Y

The end of the flanges 29 form extensions of wedge-block surface 28 and project into vthe casing beyond the apex of the triangle made by wedge faces 26 and 28 thereby providing a longer bearing with surface 12 of the easing and affording greater security against displacement of the parts inthe normal or release position of the gear. Throughout the length of the wedge block recess 30 preferably semigcircular in shape provided order that agspaceA may be available for the central column member to pass through when the wedge blocks have been moved inwardly and transversely in the manner hereinafter more fully explained. Any unevenness in the wearing or fitting of the parts is compensated for through the movement of the column on its oscillatory bearing. v

lnterposed between the wedge block pressure transmitting members 22 and coupler or front stops is a follower plate 31. A hole 32 is placed in this follower to permit the end of the column member to project beyond the end of the wedge block face 33 which engages follower plate surface 34. When the wedge blocks are moved transversely wedge block faces 33 slide along surface 34 of the follower plate thereby creating friction at these points.

The operation of the draft rigging takes place as follows z-In draft or buffmg strains the draft gear is compressed by the approach of follower to casing, the rear of the. casing abutting against rear stops in bufling strains. This movement causes wedge block pressure transmitting members 22 to be moved longitudinally into the casing 5 and by reason of the co-,acting surfaces between wedge blocks and the beveled surfaces 12 of the casing there will also be transverse movement along face 34 of follower plate 31 thus creating friction between these members. Resistance to the inward movement as well as to the transverse movement of the wedge block pressure transmitting members is set up by the friction shoes 18 and the wedge retaining member 20 supported by the springs.v As the shoes and the wedge retaining member are moved inwardly the springs are compressed, the inner springs 27 directly opposing movement of the shoes relatively to the column and therefore to the casing inasmuch as at this time the column bears on the bottom wall of the casing. The outer spring 21 due to its bearing on tie wedge retaining member forces the latter, which is preferably circular and in one piece, tightly over the cone shaped portion of the shoes causing the radialV pressure on the column to increase very rapidly as the springs compress and the pressure from this course increases. Y

It will be seen that as the wedge block pressure transmitting members 22 move transversely towards each other that the wedge faces 26 will bebrought closer to each other thereby creating a squeezing action on faces 25 of the friction shoes causing these members and the entire friction mechanism as composed by the friction shoes and wedge retaining memberto move a greater distance and therefore at a greater speed than the coupleinfollower, and wedge bloei;M pressure transmitting ymem-bers` Y The isofact that the friction shoes move at a greater speed and a greater distance than the drawbar permits the use of a comparatively weak column and relatively small bearing areas are required in order to secure the necessary foot pounds of work to effectively cushion the shock. This feature together with the employment of the movable wedge retaining member which exerts some of the radial pressure on the shoes independently of the casing permits the use of an obtuse angle between the outer end of the shoes and the wedge block pressure transmitting members thereby lessening the side thrust on the casing and still maintaining very high capacity and cushioning power throughout the required travel.

It will be observed, therefore, that the invention embraces load transmitting members, in this case the two wedge block pressure transmitting members co-operating with the casing, which for the purpose of providing high ultimate resistance with small bearing pressures cause resistance members ,to move with a greater velocity. In this case the resistance members comprise the friction shoes, and wedge retaining member co-operating with the springs and the central column.

Such a combination resisting yieldingly and frictionally is an ideal one inasmuch as the energy due to the impact of two moving cars will thereby be gradually absorbed and excessive recoil checked. Ordi narily such a combination of wedging elements as I have described and which is necessary to satisfactorily adapt the friction wedge in draft riggings to cars of modern heavy construction, would be very uncertain in its release owing to the binding of some of the friction parts.

I have therefore embodied in this invention a novel form of construction to insure the certain release of the rigging un der every condition. This consists in providing the means whereby the load transmitting members may return to the normal or release position independently of the inner friction mechanism. This feature is clearly illustrated in Figure 4 wherein the central column member is shown as being firmly gripped by the wedges and the inner coil of springs compressed between the spring seat of the column and the shoes. In this position the spring has its entire energy stored therein while theouter coil of springs, which through the medium of the wedge retaining member constitutes the means for forcing the shoes into engagement with the central column, is in the maximum release position and therefore exerts its minimum force. It will therefore be seen that in the event of the wedges binding on the central column during the releasing operation of the gear that the outer spring will expand returning the wedge retaining member with the friction shoes and the friction column being withdrawn from its seating the inner spring will remain compressed and the whole moved forward as a unit. As the releasing or expanding of the outer coil progresses its force will decrease and consequently the radial pressure on the column will decrease correspondingly until it has reached a stage when the force of the inner coil of springs, which during this time has been at its greatest, will be sufficient to withdraw the column from the shoes and return it to its seating.

While in the drawing the gear is shown with the coupler returned to the normal release position and the inner spring still fully compressed, it is pointed out that such an extreme would seldom occur in practice as the inner friction member will begin to release as soon as the pressure on the outer spring decreases but in any event it will be clearly seen that the inner friction members while serving the purpose of providing high resistance do not impede the return of the drawbar to normal position as even if the inner friction mechanism failedv to release the outer spring would still permit the draft rigging to function in both buiing and draft.

What I claim is l. A friction draft rigging comprising a casing, a follower, wedge friction blocks engageable with said follower and adapted to move transversely inwardly upon relative approach of said follower and casing and friction mechanism resisting movement of the blocks and comprising a friction post and shoes in engagement therewith, the said shoes being adapted to be moved a greater relative distance than the follower.

2. A friction draft rigging comprising f1. casing, a follower, wedge friction blocks engageable with said follower and adapted to move transversely and inwardly upon rela tive approach of said follower and casing and friction mechanism resisting movement of the blocks and comprising a friction post and shoes in engagement therewith, the shoes having at one end a wedging engagement with the wedge friction blocks and at the other end with a wedge retaining mem ber and a spring maintaining all the parts in operative engagement and resisting move ment of the friction mechanism.

3. A friction draft rigging comprising a casing, pressure transmitting blocks operatively associated therewith and adapted to move longitudinally and transversely and friction elements opposing the movement thereof, the said elements comprising a friction column, friction shoes in frictional engagement therewith and a spring opposing the movement of the same relatively to the column, wedging means for holding said shoes in operative relation with said column and a. spring resisting the movement of the said wedging means and shoes.

t. A friction draft rigging Comprising a easing, pressure transmitting blocks operatively associated therewith and adaptedto move loi'igitudinally and transversely and friction elements opposing the movement thereof, the said friction elements comprising a friction column, a plurality of friction shoes sliding thereon and a spring directly engaging the inner end of said shoes to assist in resisting movement thereof, wedging means for holding the said shoes in operative relation with said column and comprising an annular member and spring engaging this member and directly resisting ,movement of the same.

5. A friction draft rigging comprising a casing having oppositely beveled faces, wedge block pressure transmitting members sliding thereon, mechanism in said casing opposing the travel of the wedge block` pressure transmitting members and consisting of a friction column having` shoes sliding thereon and springs for maintaining the parts in frictional engagement and yieldingly opposing inward movement of the parts.

6. A friction draft rigging having transversely and longitudinally movable pressure transmitting members, load resisting members including a frictionmember and friction shoes in engagement therewith and frictionally and yieldingly opposing the movement of the pressure transmitting members and adapted to be displaced thereby and means vwhereby the pressure transmitting members may be returned to normal position independently of the release of the frietional element of the load resisting members.

7. In a draft rigging, a casing, a column, shoes in frictional engagement with the column, the said shoes being formed with exterior wedge shaped surfaces at both their outer and inner ends, the outer end of such shoes having the wedge shaped surface reacting against the casing walls'through the medium vof wedge blocksand theinner end of such shoeshaving the wedge shaped surfaces oppositely disposed to those of the a similarly tapered movable member formed to resist outward movement of f the shoes and adapted to force the same into engagement with the column and a spring yieldingly resisting inward movement of the movable parts.

9. In a friction draft rigging, a casing, a column, movable shoes having wedge surfaces, the said shoes being in sliding engagement with the column and engaging movable wedge blocks, the said wedge blocks being wedge shaped and each having a surface engaging the casing and the other surface vof the wedge block engaging one of the wedge surfaces of the shoes, the wedge blocks being formed with guides within which the shoes move.

l0. A draft rigging having a friction element, the bearing surfaces of which element are angularly disposed and meet in a line, one of such surfaces having a portion thereof extending beyond this line.

1l. In a friction draft rigging, a casing, a column within the casing and bearing on the casing bottoni wall, the said column having a spring seat formed thereon; friction shoes in engagement with the column and a spring bearing on the said friction shoes and on the spring seat of the column, wedging means for holding the said shoes in operativerelation with the column and a spring bearing on the said wedging means and on the casing bottom wall.

In testimony whereof I have hereunto set my handA in the presence of two witnesses.

GEORGE BINET DOREY. Witnesses: Y

P, J. BINET, A, J. BALLEINE. 

